Fossil Record

Classification of Trilobites

Trilobites are divided into nine orders with arthropoda class trilobita (it becomes 10 if Order Odontopleurida (Superfamily Odontopleuroidea and Superfamily Damesellidae within Lichida) is separated from Order Lichida

Trilobite Classification

Trilobite Phylogeny

Phylum Arthropoda
Subphylum Chelicerata
or Subphylum Trilobitamorph
Superclass Arachnomorpha *
Class Trilobita

    Order Agnostida
    Order Redlichiida
    Order Corynexochida
    Order Phacopida
    Order Lichida
    Order Proetida
    Order Harpetida
    Order Ptychopariida
    Order Asaphida
    Order Odontopleurida **
    Order Nectaspida

o Arthropoda
`--o Trilobita
   |?-Agnostida
   |?-Eodiscina
   `--+--o Redlichiida
      |  |--Olenellina
      |  `--Redlichiina
      |--Corynexochida
      |--Phacopida
      |--Lichida
      |--Odontopleurida
      `--o Librostoma
         |--Proetida
         |--Harpetida
         |--Ptychopariida
         `--Asaphida

* Several alternative taxonomies are found in past and current literature. For example, trilobites are sometimes found placed in arthropoda subphylum Schizoramia within Superclass Arachnomorpha.
** Some trilobite workers argue that a separate Order Odontopleurida should be separated from Order Lichida, and the change is likely to be done by concensus.

Trilobites Classification

Classification of Trilobites